How do I write that an variable is (or not) an integer, or my integer variable does not have value ?
You declare a variable to what you need it to be
OK, i know
and after that as the situation changes I give a value to N, like N = 2 or N = 1 etc,
N can be 0>, 0< or 0.
but before these situations N does not have a value, I need to do something when N still does not have value.
Try with NULL: Void Type and NULL Constant
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